WO2024028749A1

WO2024028749A1 - Use of a lamella clarifier in a sedimentation device of an apparatus for the treatment of oil- and/or fat-containing waste water

Info

Publication number: WO2024028749A1
Application number: PCT/IB2023/057757
Authority: WO
Inventors: Michael Kühlwein
Original assignee: TEC Austria GmbH; Michael Kühlwein
Priority date: 2022-08-01
Filing date: 2023-07-31
Publication date: 2024-02-08
Also published as: DE102022119273A1

Abstract

The invention relates to the use of a lamella clarifier (230) in a sedimentation device (200) of an apparatus (2) for treating oil- and/or fat-containing waste water, the apparatus (2) comprising the following elements: - an inlet (4) for supplying the water to be treated, - a preliminary separator (110) for preconditioning and sedimentation and for further removal of fat, the removed fat being collected in a collection container (112), - a sedimentation device (200), connected downstream of the preliminary separator (110) via a conduit (130) to a metering unit (140) for coagulants (10), for sedimentation of suspended solids out of the water to be treated, wherein the sedimentation device (200) comprises at least - an enrichment path (8) for enriching the water to be treated with a coagulant (10) and - a regulation path (18), downstream of the enrichment path (8), for introducing a regulation agent (22) that adjusts the pH of the water to be treated, - a filter device (28), downstream of the sedimentation device (200), having a filter medium (30) and - a reverse osmosis device (40), downstream of the filter device (28), for further cleaning of the water, wherein - the apparatus is designed to treat an influent volume of less than 1000 l/h.

Description

FROM BÜLOW & TAMADA

ROTBUCHENSTR. 6 Patent Attorney D-81547 MUNICH DR. TAM AXEL VON BÜLOW TEL: +49-(0)89-642 30 94 LAW FIRM FOR INNOVAT (retired) FAX: +49-(0)89-64 63 42 IONSSCHUTZ

Patent attorney

EMAIL: office@vb-t.com SASCHA TAMADA

Lawyer

ALEXANDER GINZBURG

Patent attorney LIANJI JIN

July 31, 2023

Applicant: TEC Austria GmbH

Applicant reference: B-P-X0-R396-009-XP-1

Use of a lamella clarifier in a sedimentation device of a device for treating wastewater containing oil and/or fat

Description

The present invention relates to the use of a lamella clarifier in a sedimentation device for the treatment of wastewater containing oil and/or fat.

Multi-stage water treatment in the sedimentation device can enable both the reduction and/or removal of hardness formers, in particular calcium ions, and also lead to a reduction in TOC (total organic carbon) in drinking water. Although this two-stage procedure is well known, it is not the standard procedure for water treatment and is usually contradictory. TOC reduction is typically achieved by a low pH between 4.0-7.3, and reduction of hardness agents can typically be achieved at higher pH values between 9.5-11.5. The presence of TOCs also acts as an inhibitor in the precipitation of calcium.

Carrying out this special process typically requires extensive subsequent steps that involve dimensioning the system almost unsuitable for the use of 50 PE (population values) - 1000 PE. Such information is used, among other things, to specify small sewage treatment plants in accordance with DIN EN 12566 (Al version from 2003) and DWA-A 222.

The area of application of the system according to the invention for water treatment and in particular water treatment should preferably be in the range of up to 1000 PE, preferably up to 200 PE, and particularly preferably up to 50 PE.

A decisive advantage of using such a system is its small space requirement and the low number of maintenance cycles required.

Based on this preliminary consideration, the aim of the present invention is to provide a water treatment system for a comparatively small water volume of less than 1000 PE. It is characterized by a compact design and almost maintenance-free operation with the highest possible cleaning efficiency.

The present invention solves this problem by using it with the features of claim 1.

According to the invention, a lamella clarifier is used in a sedimentation device for the treatment of wastewater containing oil and/or fat.

The device includes the following elements:

- an inlet for supplying the water to be treated,

- a pre-separator (110) with a skimming device (111) in the form of a belt skimmer for additional fat separation, the skimmed fat being collected in a collecting container (112),

- which connects to the pre-separator (110) via a line (130) with a metering unit (140) for coagulants (10). Sedimentation device (200) for sedimentation of suspended matter from the water to be treated, wherein the sedimentation device (200) has at least one enrichment path for enriching the water to be treated with a coagulant and a regulation path adjoining the enrichment path for introducing a pH-adjusting path for the water Has regulatory means, and

- a filter device connected to the sedimentation device with a filter medium and

- A reverse osmosis device connected to the filter device for further purification of the water.

The sedimentation device does not have to be directly connected to the inlet, but additional cleaning devices, in particular a grease separator and/or a skimming device, can be arranged between the inlet and the sedimentation device.

The system is designed to process an inflow volume of less than 1000 l/h. This is a small water treatment plant.

The use of a lamella clarifier in such small systems is not yet known. It enables a particularly compact design of the system. The stages of sedimentation, filtration and reverse osmosis are required at the same time to enable efficient treatment of wastewater with above-average dirt loads.

In order to achieve the described purpose, various means and methods can be used. The fat separator enables the separation of fat and other settleable substances from the kitchen water. The pre-separator serves both as a sedimentation tank and for further fat separation, for example by a Ribbon skimmer. It helps to skim off floating fat and improves the water quality for the subsequent process steps. The sedimentation device enables the removal of impurities through the sedimentation of flocs formed by the addition of coagulum (e.g. iron (III) solution). The reverse osmosis system removes dissolved substances and produces high-purity permeate that can be used for toilet flushing or garden irrigation. The concentrate, which can reduce wastewater flow by up to 70%, can be directed back into the grease separator. This increases the COD concentration and the dissolved and undissolved components of the wastewater are bound in the sludge. The concentrated sludge can be sent to a drying system to be processed into fertilizer for organic farming. The pH of the wastewater can be adjusted to a neutral or slightly alkaline value to facilitate flocculation and sedimentation. By backwashing, colloids and/or bacteria can be removed from the surface of the rotating membrane and flushed out or recirculated as retentate. The permeate can be disinfected with a disinfectant (e.g. chlorine) before use for toilet flushing or garden irrigation.

By combining these different means and processes, kitchen water can be almost completely cleaned of fats, semi-volatile lipophilic substances and settleable substances, making it suitable for use as industrial water (e.g. for toilet or garden irrigation). At the same time, the dissolved and undissolved ingredients are bound in the sludge and can be processed in the drying system into a fertilizer for organic farming.

Advantageous embodiments of the invention are the subject of the subclaims.

The lamella clarifier can have a housing with a longitudinal axis, with the angle of inclination of the lamellae being between 2-45°, preferably 5- 25 ° is formed relative to the longitudinal axis of the housing. This increases the effective clarification area and at the same time allows the sedimented solids to slide towards a bottom area due to gravity.

The average lamella spacing in the lamella clarifier can be between 1-8 cm, preferably between 2-4 cm. Such a spacing between the slats is rather unusual for larger amounts of water.

The lamella clarifier can preferably have a bottom area that is conical and has a sludge outlet. This results in the sludge being collected and compacted.

In addition, the lamella clarifier can have a level measuring device and/or one or more limit switches, preferably a capacitive level measuring device. The level measuring device is used both to determine and/or monitor the level of the liquid and to determine and/or monitor the phase boundary between sludge and liquid. The monitoring can also simply include the detection of reaching a limit level. Accordingly, emptying can take place if there is too much sludge phase or if the overall level is too high. It is known that changing the composition results in a change in capacity. For example, capacitive level measuring devices are also used to detect a foam phase and its filling level.

In addition, the sedimentation device can have a control and evaluation unit which serves to regulate the sludge outlet depending on the level of the phase boundary. This means that the sludge outlet can be opened and closed not only based on the overall fill level, but also in the event of heavy sludge formation, where the clarifier works inadequately above a certain sludge level.

The sedimentation device can have a sludge collection container have a sludge collection room into which the sludge is led from the sludge outlet of the lamella clarifier. The sedimentation device also has a filter medium that partially limits the sludge collection space. The filtrate can be collected in a liquid collection space in the sludge collection tank.

The filter medium can preferably be designed as a disposable filter medium, particularly preferably as filter paper. This is also a special feature of the present invention, since the use of expensive ceramic filters at this point makes no sense in a small system and a filter paper is sufficient to concentrate the sludge.

The sludge collection container can also be filled level monitored, here too both the level of the phase boundary between water and sludge and the overall fill level can be determined and/or monitored. In this case, a level measuring device can also be used.

The sedimentation device can have a control and evaluation unit which is set up to control the emptying of the sludge collection container depending on the fill level.

The sedimentation device can have a drying system for drying the sludge phase.

In addition, the sedimentation device can have a return line which serves to return a filtrate from the sludge collecting container into a fat separator or a fat separation device upstream of the sedimentation system. This fat separator device preferably works according to the principle of phase separation caused by gravity. This reduces the volume of waste streams.

In addition, the lamella clarifier can have cleaning agents in a CIP process. This is also rather unusual for small systems and enables further automation of the operation of the system.

The small system makes it possible to process water with a very high fat content and a COD value of more than 3,000 mg/l on average. Such kitchen wastewater occurs, for example, in system catering.

The characteristics, features and advantages of this invention described above and the manner in which these are achieved will become more understandable in connection with the following description of the exemplary embodiments, which will be explained in more detail in connection with the drawing. Show it:

Fig. 1 shows a schematic diagram of a method according to the invention and a system.

The figure is a purely schematic representation. Actual geometric relationships may vary from the figure.

Reference is made to Figure 1, which shows an apparatus 2 for treating water. The water is particularly kitchen water with a high content of fat and other compounds produced in the kitchen.

The device 2 comprises an inlet 4, via which the water to be treated is supplied in a flow direction 5, also referred to as the flow direction. The inlet 4 can include a kitchen siphon.

After the inlet 4, the device has a grease separator 100, which is arranged immediately downstream of the inlet in the direction of flow.

The maximum inflow quantity of water to be treated, in particular kitchen wastewater, to be processed by the method according to the invention System can be at least 100 l/h, preferably between 150-500 l/h.

The grease separator 100 has a container 101 which delimits a receiving space 113. The container 101 has at least one partition 102, which segments the container into at least two separation areas or chamber segments 104, 105. A line 103 between the inlet 4 and the grease separator 100 serves to feed the water to be treated into the first separation area 104. The second separation area 105 has an overflow 106. The partition 102 can in particular be designed as a baffle. The filling level of the first and/or second separation area 104, 105 is monitored via a filling level sensor 107, for example a float.

Furthermore, the grease separator has a ventilation device 108 for introducing an oxygen-containing gas, in particular compressed air, into the water to be processed in the container 101.

The ventilation device 108 is preferably arranged immediately after a connection coupling of an inlet 2 of the device for connection to a kitchen drain, in particular a siphon. This reduces the amount of COD immediately after the inflow, which prevents the system from tipping over into the anaerobic state.

This leads to mixing and prevents the water from becoming anaerobic. The pressure should be at least 2 bar, preferably 3-5 bar. The ventilation device 108 can have a system for generating compressed air 109. A compressed gas nozzle 120, which is fixed to the wall of the container 101 in a medium-tight manner, for example, has an inlet opening for gas into the water to be cleaned and is arranged in the lower region of the liquid level of the container 101, so that a sufficiently large distance is provided in which oxygen can be introduced into the liquid. The water to be treated is then transferred, in particular pumped, into a pre-separator 110. The pre-separator 110 serves on the one hand as a sedimentation tank and on the other hand for further fat separation by a skimming device 111 in the form of a so-called belt skimmer 111.

Band skimmers or band skimming devices are known in larger systems. Floating fat is skimmed off with the help of a conveyor belt. However, practical use has shown that the fat content of the water to be treated is still surprisingly high despite the previous fat separator, so that the use of the belt skimmer 111 significantly improves the water quality for the subsequent process steps.

The skimmed oils and fats are collected in a collecting container 112 and disposed of professionally together with other fats that occur in the kitchen, such as frying fat and drippings, by an appropriate disposal company.

After this pretreatment, the water to be treated is optimally prepared for subsequent sedimentation. The water to be treated is passed from the pre-separator 110 via a line 130 into a sedimentation device 200, which includes a lamella clarifier 230 in which the sedimentation of impurities takes place. In the transition between the pre-separator 110 and the lamellar clarifier, a coagulum 10, preferably an iron (III) solution, particularly preferably as an iron (III) chloride solution, is added. A corresponding dosing unit 140 for adjusting the flocculant content is arranged along line 130. Part of the line 130 and the dosing unit 140 are part of an enrichment path 8 of the sedimentation device 200. The lamella clarifier preferably has a level measuring device 231 and/or a limit switch. Ideally, the level measuring device 231 and/or the limit switch or an arrangement of several detects Limit switches determine both the total filling level and the filling level of the sludge or phase boundary, with emptying taking place not only based on the total filling level, but based on one of the two values. A capacitive sensor can be used for this, which detects the phase boundary based on a change in capacitance.

In addition, the pH value is adjusted to a neutral or slightly basic value, preferably between 7.2-7.5. This can be done in particular by adding a regulating agent 22, preferably a basic agent, particularly preferably NaOH, in particular a NaOH solution , take place. A dosing unit 150 for adjusting the pH value is arranged along line 130. The dosing unit 150 and/or the line 130 and/or a means arranged along the line may have a pH sensor 151, which is connected to the dosing unit 150 by means of a signal connection, as a wireless connection or as a signal cable. In particular, the dosing unit 150 can have a control and evaluation unit for processing the measurement signals from the pH sensor 151 and for adjusting the dosage amount of the basic agent to the water to be treated. Another part of the line 130 and the metering unit 150 are part of the regulation path 18 of the sedimentation device 200.

The flow path is designed in such a way that there is sufficient time for flocculation. A means 160 for reducing the flow velocity is arranged between the pre-separator 110 and the sedimentation device 200. The means can be arranged along the line 130 or in the line 130 or be part of the line 130. This facilitates sedimentation and reduces the tendency for turbulence. The means 160 for reducing the flow velocity is particularly preferably designed as a tubular reactor. The tubular reactor can have a temperature control device to provide constant binding conditions.

The sedimentation device 200 has a lamella clarifier 230, which has a conical partial segment 201 on the bottom for settling the Has sediments, at the tapering end of which there is a mud drain 202. In a neutral to basic pH value, hydroxide flakes form in the sedimentation device 200, in particular iron hydroxide flakes, which bind approximately 90% of the undissolved substances and 50% of the dissolved substances. The sedimented sludge is periodically discharged into a sludge collection tank 250 with a DM content of preferably 3-5%.

The sludge collection tank 250 has a sludge collection space 255 and also has a conical bottom 251 with a sludge drain 252 at the tapered end of the bottom 251. The sludge collection tank 250 also has a fill level sensor and / or a fill level limit switch 253. When a predetermined fill level is reached, a The sludge collection tank 250 must be emptied. By monitoring and/or determining the fill level, optimal post-sedimentation within the sludge collection tank 250 is achieved.

The sludge collection tank 250 has a permeable filter element 254, which preferably forms a wall region 256 of the sludge collection space 255, particularly preferably the conical bottom 251. Preferably, the permeable filter element 254 is a filter paper or filter cloth.

In the sludge collection tank 250, a liquid collection space 257 is arranged beyond the sludge collection space 255. The retentate of the filter element 254 is collected in this liquid collection space 257, while the permeate remains in the sludge collection space 255, whereby the sludge phase is further concentrated. This preferably takes place over a period of 12-24 hours.

The retentate 258 is then returned from the liquid collection space 257 into the pre-separator 110, while the concentrated sludge 259, preferably after reaching the predetermined fill level, from the sludge collection space 255 and the Sludge collection tank 250 derived and can be fed to a drying system 260, for example biological drying. A process for biological drying is basically known and a corresponding exemplary process for biological drying of sewage sludge is disclosed, among others, in DE 41 11 314 C2. The aforementioned document only describes a variant within the scope of the present invention and can also be done in another way. The dried sludge can then be processed into fertilizer, preferably together with collected food waste from the collecting container 112.

The sedimentation device 200 has a plurality of inclined slats 203, which are arranged obliquely at an angle of 2-45°, preferably 5-25°, compared to a vertical orientation of the slats. The sedimentation device designed as a lamella clarifier can also have a longitudinal axis 204, which is preferably arranged parallel to the vertical direction. The flow through the plate pack is from bottom to top. A gaseous medium, in particular air, can be blown in to support this and preferably. Accordingly, the sedimentation device 200 has a gas inlet, not shown, which is preferably arranged below individual lamellae or a lamella package.

The sedimentation device 200 also has an inlet opening 205, at which the line 130 opens into the sedimentation device 200. The inlet opening 205 is arranged above the sludge outlet 202. In addition, the sedimentation device 200 has an outlet opening 206 for a clarified liquid phase, which is arranged above the inlet opening 205. A transfer line 220 is arranged at the drain opening 206. An overflow weir, not shown, is preferably arranged within the sedimentation device 200 and is arranged in the area of the drain opening 206.

The transfer 220 then opens into a storage container 310 Ultrafiltration system 300. The ultrafiltration system 300 also includes a dynamic tangential flow filtration system (cross flow) 320 with one or more ceramic filtration disks 332 rotatably mounted in a housing 331. The average pore size of the ceramic disks can advantageously be between 10-50 nm. They define a so-called ceramic rotation membrane. The pre-cleaned wastewater is circulated between the dynamic tangential filtration system 320 and the storage container 310. A filtrate between 50-500 l/h, preferably between 150-400 l/h, is directed towards a receiver tank 410 of the reverse osmosis system 400. The ultrafiltration system has appropriate means, for example a pump, one or more lines and a control unit, which flushes the rotary membrane, preferably by generating backwash pulses. To control the periodicity of the generation of the backwash pulses, a sensor unit can be provided, in particular on a discharge line of the filtrate. A sensor unit can be, for example, a pressure sensor and/or an optical sensor for determining a turbidity content in the filtrate and/or a flow sensor.

Due to the return pulses, colloids and/or bacteria are removed from the surface of the rotating membrane and can be rinsed out as retentate or recirculated into the storage container 310, thereby concentrating the supplied phase.

Short-chain fatty acids, which can cause a significant odor nuisance, such as butyric acid, are not retained and are collected as part of the filtrate in the receiving tank 410 of the reverse osmosis system 400.

The reverse osmosis system 400 is equipped with a membrane 402 and is operated with a yield rate of preferably more than 60% by volume, preferably between 65-75% by volume. Reverse osmosis is known per se. The system is designed for a maximum delivery of more than 100 l/h, preferably for a maximum delivery of one Quantity between 120-300 l/h. It has an osmosis container 410, for example with a wound membrane or another semi-permeable membrane 411, and an adjoining storage tank 420 for the permeate. The reverse osmosis system 400 has a drain line 430 for the permeate, which is arranged on a permeate drain 401 of the reverse osmosis system.

The permeate provided meets all the requirements for introduction into a conventional water network and can be used, for example, to flush toilets. Therefore, the drain line 430 can advantageously have a connection 431 to a sanitary facility. The storage tank 420 is part of the drain line 430. The storage tank 420 also has a fill level and/or limit level monitoring device 421, which initiates emergency emptying when a certain limit level in the storage tank is reached.

A disinfection dosing unit 440 for feeding a disinfectant into the permeate is also arranged along the drain line 430. The disinfection dosing unit 440 has a storage tank with disinfectant for water disinfection of a predetermined concentration. Typically this can be chlorine or another disinfectant such as NaCIO, in particular between 0.1-1 ppm.

Furthermore, an activated carbon filter 450 is provided in or on the osmosis container 410 or along the drain line 430. This is preferably arranged in front of the disinfection dosing unit 440 in the direction of flow.

The osmosis container 410 has a concentrate drain 412, which is used to drain off a concentrate. The concentrate, which contains the impurities remaining after ultrafiltration, is returned to the grease separator 100 via the concentrate drain 412. An increased COD content of up to 3300 mg/l compared to 1000 mg/l can be detected in the concentrate. Because of the comparative Due to the small amount of waste water in the concentrate, the dirt load is not of significant importance.

Detachable substances are completely removed and semi-volatile lipophilic substances are largely removed by the device 2 described above.

Samples of kitchen wastewater were taken over a period of one year and various parameters were determined through full analyses:

1. Kitchen water before discharge

Amount of wastewater (m3/d) = 1.9

Semi-volatile lipophilic substances, calculated as TR (mg/l) <150

COD calculated as 02 (mg/L) <1000

Detachable substances, calculated as ABS (ml/l) < 10

Temperature (°C) <35

2. Kitchen water at the ultrafiltration filtrate outlet

Amount of wastewater (m3/d) = 1.9 pH value 7.0 - 7.5

Semi-volatile lipophilic substances, calculated as TR (mg/l) <5

COD calculated as O2 (mg/l) <1000

Settable substances, calculated as ABS (ml/l) < 1.0

Temperature (°C) <35

3. Kitchen water at the reverse osmosis concentrate drain

Amount of wastewater (m3/d) = 0.57 pH value 7.0 - 7.5

Semi-volatile lipophilic substances, calculated as TR (mg/l) <20 COD, calculated as O2 (mg/l) <3333

Settable substances, calculated as ABS (ml/l) < 2.0

Temperature (°C) <35

4. Kitchen water at the permeate outlet of the reverse osmosis waste water volume (m3/d) = 1.33 pH value 6.5 - 7.5

Semi-volatile lipophilic substances, calculated as TR (mg/l) <2.0 COD, calculated as 02 (mg/l) <200

Settable substances, calculated as ABS (ml/l) < 0.5

Temperature (°C) <35

The aforementioned method and the aforementioned device process kitchen water from system catering (QSR) into service water, which is suitable for flushing toilets or for watering gardens.

All of the resulting kitchen water is almost completely purified of low-volatility lipophilic substances (SLS) and settleable substances (ABS). The pH value of the wastewater is neutralized. The reverse osmosis concentrate, which reduces the wastewater flow by 70%, has an increased COD concentration while maintaining the same dirt load after ultrafiltration treatment when it returns to the grease separator. The dissolved and undissolved ingredients of the wastewater are bound in the sludge, which can be processed in the dryer together with leftover food into fertilizer for use in organic farming.

List of reference symbols Device inlet Flow direction Enrichment path Coagulant Regulation path Regulating means Grease separator Container Partition wall Lines Separation area Separation area Overflow Level sensor Ventilation device Device for generating compressed air Pre-separator Skimming device Collection container Receiving space of the container of the fat separator Compressed gas nozzle Line Dosing device Dosing unit Sensor Means for reducing the flow velocity Sedimentation device Sub-segment Sludge drain Oblique slats Long axis Inlet opening 206 drain opening

210 template containers

220 transition

230 lamella clarifiers

231 level gauge

250 sludge collection tank

251 floor

252 mud drains

253 Level sensor and/or level limit switch

254 filter element

255 mud collection room

256 wall area

257 liquid collection room

258 retentate

259 concentrated mud derived

260 drying system

300 ultrafiltration system

310 storage containers

331 housing

332 ceramic filtration discs

400 reverse osmosis system

401 Permeate drain

410 master tank / osmosis container

412 concentrate drain

420 storage tank

421 level and/or limit level monitoring device

430 drain line

431 connection (sanitary system)

440 disinfection dosing unit

450 activated carbon filters

Claims

Patent claims

1. Use of a lamella clarifier (230) in a sedimentation device (200) of a device (2) for treating wastewater containing oil and / or fat, the device (2) comprising the following elements: an inlet (4) for feeding the wastewater to be treated Water, a pre-separator (110) for preconditioning and sedimentation as well as for further fat separation, the separated fat being collected in a collecting container (112), which is connected to the pre-separator (110) via a line (130) with a metering unit (140). Coagulants (10) subsequent sedimentation device (200) for sedimentation of suspended matter from the water to be treated, the sedimentation device (200) having at least one enrichment path (8) for enriching the water to be treated with a coagulant (10) and one adjoining the enrichment path Regulatory path (18) for introducing a regulating agent (22) which adjusts the pH value of the water, a filter device (28) connected to the sedimentation device (200) with a filter medium (30) and a reverse osmosis device connected to the filter device (28). (40) for further purification of the water, the device (2) being designed to process an inflow volume of less than 1000 l/h.

2. Use according to claim 1, characterized in that the lamella clarifier (230) has a housing with a longitudinal axis (204), the angle of inclination of the lamellae (203) being between 2-45°, preferably 5-25°, relative to a longitudinal axis ( 204) of the housing is formed.

3. Use according to one of the preceding claims, characterized characterized in that the average slat spacing of the slats (203) of the slat clarifier (230) is between 1-8 cm, preferably between 2-4 cm.

4. Use according to one of the preceding claims, characterized in that the lamella clarifier (230) has a bottom area (201) which is conical and has a sludge outlet (202).

5. Use according to one of the preceding claims, characterized in that the lamella clarifier (230) has a level measuring device (231) and/or at least one limit switch, preferably a capacitive level measuring device, for monitoring and/or determining a level of the liquid and a phase boundary between sludge and liquid and wherein the sedimentation device (200) has a control and evaluation unit which is designed to regulate the sludge outlet depending on the level of the phase boundary.

6. Use according to one of the preceding claims, characterized in that the sedimentation device (200) has a sludge collection container (250) with a sludge collection space (255) and with a filter medium (254) which partially delimits the sludge collection space (255), the filter medium (254) is preferably designed as a disposable filter medium, particularly preferably filter paper.

7. Use according to one of the preceding claims, characterized in that the sludge collection container (250) is monitored for fill level, the sedimentation device (200) having a control and evaluation unit which is set up to control the emptying of the sludge collection container (200) depending on the fill level .

8. Use according to one of the preceding claims, characterized characterized in that the sedimentation device (200) has a

Drying system (260) for drying the sludge phase.

9. Use according to one of the preceding claims, characterized in that the sedimentation device (200) has a return line (258) for returning a filtrate from the sludge collection container (250) into a fat separator (100) upstream of the sedimentation system (200).

10. Use according to one of the preceding claims, characterized in that the lamella clarifier (230) has means for cleaning in a CIP process.

11. Use according to one of the preceding claims, characterized in that the water to be treated is a fatty kitchen wastewater with a COD value of on average more than 3,000 mg/l.